An anchoring rail of the type in question is known from EP 2 478 163 B1. Anchoring rails of this type are cast into concrete in order then to be able to fasten objects thereon with the aid of rail nuts, engage behind parts, head screws or hammer head screws. Together with such fastening elements, the anchoring rail forms a fastening system. The weight of the fastened objects is transmitted via the rail geometry and the anchor of the anchoring rail into the concrete. In the process, cracks may arise in the concrete. For the controlled formation of cracks, crack initiator means are provided on the anchoring rail in EP 2 478 163 B1.
In addition to a possible failure of the fastening of the anchoring rail in the concrete, a failure of the material of the anchoring rail itself is the greatest source of uncertainty for an anchoring rail based fastening system. Under landing by the weight of an object fastened to an anchoring rail or due to other forces, the connecting point of anchor and rail of the anchoring rail is exposed to a large loading. Some of the weight is transmitted to the base of the anchoring rail via the limbs and the side walls of the anchoring rail. This may lead to deformation of the anchoring rail, wherein the region of the connection of anchor and base is typically secured by the anchor secured in the concrete and the regions of the base that are further away from the connecting point are bent in a direction away from the anchor. In a following step, the base may tear out at the connecting point between base and anchor, whereupon the stability of the entire anchoring rail and the fastening thereof is impaired. A further point of weakness of the anchoring rail is represented by the free limbs of the anchoring rail. A large part of the weight of a fastened object is typically transmitted via the head of a head screw to the free limbs of the anchoring rail. In this connection, the free limbs may bend upward in a direction away from the anchor of the anchoring rail. In the extreme case, the free limbs of the anchoring rail are bent up to such an extent that the head of the head screw can no longer be held in the slot formed between the free limbs in the longitudinal direction of the anchoring rail. This also greatly impairs the stability of the anchoring rail.